How to Convert and Render Prebid Server Bids
BiddingStack can rewrite a Prebid Server bidder's response so it renders through the BiddingStack ad-tag SDK. This lets you turn native or video demand into standard display slots, resize mismatched banners, and place any creative in high-impact formats such as floating footers or fullscreen prestitials, without any changes on the page.
You configure this per bidder, on each placement, under the bidder's Prebid Server settings.
Where to Find It
- Open your project and go to Placements.
- Edit a placement and expand the Prebid Server bidder you want to configure.
- Set Prebid Server Convert Mode and, optionally, the Render Options below it.
Convert Modes
| Mode | What it does | Use it when |
|---|---|---|
| None | No conversion. The bid renders as returned by the bidder. | Default. |
| Native to Banner | Converts a native bid (image, title, description) into a display creative rendered in the ad slot. | You want native demand to fill standard banner slots. |
| Native to Template | Converts a native bid and renders it in a high-impact template (prestitial, floating footer, etc.). | You want native demand in premium formats. |
| Video to In-Banner Video | Converts a VAST video bid into an in-banner (or prestitial) video played by the BiddingStack player. | You want video demand to fill display slots. |
| Banner to Banner (Resize) | Requests other creative sizes from the bidder and responsively scales the winning creative to fit your slot. | Your slot size has little demand, but nearby sizes do. |
| Banner to Template | Takes a banner bid and renders it in a high-impact template instead of the original slot. | You want display demand in premium formats. |
For Banner to Banner (Resize), also set Convert Sizes, the sizes requested from the bidder (for example 728x90). The creative is scaled to fit your slot while keeping its aspect ratio.
Render Templates
For Native to Template and Banner to Template, choose a Render Template:
- Prestitial Banner: fullscreen overlay with countdown and close button.
- Prestitial Video: fullscreen overlay video.
- Sticky Banner: sticks to the bottom of the screen.
- Float Header Banner: floats at the top of the page.
- Float Footer Banner: floats at the bottom of the page, with a minimize button.
- Dynamic Footer Banner: responsive corner unit; uses your slot size on desktop and a configurable smaller size on mobile.
Render Options
Render Options fine-tune how the converted ad displays. All fields are optional; anything left on Default or blank keeps the renderer's built-in behavior. The available options change with the effective placement:
All placements
- Placement Override: force a specific placement (in-slot, header, footer, dynamic footer, footer max, prestitial). Overrides the Render Template.
- Close Button: show or hide the close button.
Prestitial
- Countdown (seconds): how long before the ad can be closed.
- Background Overlay: dim the page behind the ad.
- Auto Close After Countdown: close the ad automatically when the countdown ends.
- Close On Overlay Click: let users dismiss the ad by clicking outside it.
Floating Footer
- Minimize Button: let users collapse the ad instead of closing it.
Dynamic Footer
- Corner Position: bottom left or bottom right.
- Mobile Width / Mobile Height (px): ad size on mobile; desktop uses the slot size.
Video
- Replay Button: show a replay control when the video ends.
- Player Timeout (ms): how long to wait for the player to load (default 10000).
Banner to Template only
- On-Page Rendering (Scale-Fit): On renders the creative directly on the page with responsive scale-to-fit (use for trusted demand only). Off (default) renders in a sandboxed iframe for isolation.
Advanced
- Media Type Override: forces a specific renderer (banner, native, video). Leave on Default unless instructed by support.
- Slot Width / Height Override (px): overrides the detected slot size.
Use Cases
BiddingStack setups that unlock extra demand while staying respectful of the user experience:
Desktop leaderboard demand in a mobile sticky footer
Use Banner to Banner (Resize) with Convert Sizes 728x90 on a 320x50 mobile footer placement; the leaderboard scales to fit the small slot. Or use Banner to Template with the Float Footer Banner template and keep the Minimize Button on, so users can collapse the unit.
Vertical banners as a mobile corner unit
160x600 / 300x600 demand has nowhere to render on mobile. Banner to Template with the Dynamic Footer Banner template plus Mobile Width / Height (for example 120x240) shows the resized vertical creative in a dismissible bottom corner; content stays fully readable.
Native demand fills empty banner slots
Many bidders have strong native budgets but no banner creative for your sizes. Native to Banner lets the BiddingStack ad-tag assemble the image, title, and description into a clean display ad inside the existing slot, with no new UI on the page at all.
Video budgets in display slots
Video to In-Banner Video plays VAST demand muted inside a standard MPU with a Replay Button. Video CPMs typically beat display in the same slot, and the fixed slot size means zero layout shift.
Full-screen moments, kept polite
Native to Template or Banner to Template with the Prestitial template works well between page views. Keep the Countdown at 3-5 seconds, Close Button on, and Auto Close After Countdown on so the ad never traps the user.
Odd-size slots backfilled by popular sizes
A 320x250 or 336x250 slot can request 300x250 via Banner to Banner (Resize); near-identical aspect ratio, above 90% scale, visually indistinguishable, and dramatically more bidders competing.
Tips
- Start with a single bidder and mode, verify the render on your page, then expand.
- Prestitial and floating formats are intrusive; keep countdowns short and close buttons enabled for a good user experience.
- If an ad does not render, check the browser console and see How to Debug Your BiddingStack Integration.
Need help choosing a setup? Contact the BiddingStack team and we'll recommend a configuration for your inventory.